Pneumatic:

Hydraulic:

Smart Way To Do Job Cuts Time In Half

When Kootenay Industrial Contractors, Ltd., bid on the job to remove a 16-in. thick layer of deteriorating concrete from the face of three steep spillways at a hydroelectric dam, general manager Sante Pulice figured he had two choices:

His crews could do the job the hard way-standing on platforms and wrestling with jackhammers;

Or they could do it the smart way-using compact excavators equipped with hydraulic breakers.

He chose the smart way. That cut the time required by at least 50 percent.
This was part of a project to reface three spillways, each 34-ft. wide and 100- to 120-ft. long with a 60-degree slope, at the Brilliant Dam on the Kootenay River near Castlegar, B.C. The demolition phase required Pulice’s crews to remove 785 cu. yds. (600 m³) of concrete. They used four Bobcat 331 excavators with 2560 and 2570 hydraulic breaker attachments from Bobcat of Castlegar.
“We finished the concrete demolition in six weeks,” Pulice reports. “It would have taken 18 men with jackhammers probably 12 to 14 weeks to do the job.”

Excavators Work From Platforms

A pair of the excavators each worked from a timbered steel-beam platform. A 40- ton crane loaded the excavators on the platforms. Working from the top of the spillway down, each platform was lowered and raised by 10-ton air winches. Once in place, the platforms were secured by threaded steel bolts, anchored 4-ft. deep into the spillway face.
“The excavators worked eight hours a day,” Pulice says. “Each machine removed from .7 to 1 cu. yd. (.5 to .75 cu. m) of concrete per hour, which met our expectations.”
Long, narrow buckets on the platforms collected the concrete as it was removed, protecting the river from debris. When full, a crane lifted the buckets, dumping them into trucks for removal. The crane was also used to lower buckets of fresh concrete for refacing the spillways.
Safety, of course, was a key concern.
“We always had to be aware that we were working at an operating power-generation facility,” he says. “Whenever our guys were walking on the platforms or on the spillways they were secured by safety lines from the top of the dam.”
Once all the concrete was removed, a rotary air drill bored holes into the spillway face to mount anchor bolts for the rebar, prior to pouring new concrete.
“It was a tough project, but the Bobcat excavators made it a lot simpler,” Pulice says. “They worked very well. Unlike men who get tired as the day goes on, the excavators don’t. So production stays up all day long.”